signal amplitude: dry Ultracortex with P300 or cVEP [resolved]
I bought the Ultra "Mark IV" EEG Headset around 3 months ago. Ever since the last time I posted on this forum and even before that, the quality of the signals that come from my headset is not good.
The issue is that even when using OpenVibe to classify the signals as P300 or not, the classifier does not detect any P300 signals. The potential issues that came to mind were latency/timing issues, how worn out the electrodes are, and the signal quality that come from the electrodes themselves.
The impedance values according to other forums, were not bad on the OpenBCI GUI.
From the last post I put on this forum, I was told to change the latency settings in the Ubuntu 16.04 VM I had, which I did; however, the classifier from OpenVibe still did not predict any P300 signals. Therefore, I chose the suggested alternative MindAffect software. I relocated the electrodes to the back of the headset, as the directions stated.
After running the SNR test from their Python API on my base Windows system, the values were always too high, unless a drastic change was made to the headset at the moment-- for example, moving the headset rapidly to the side. I wondered if this was an issue with being too close to other devices that may have interrupted the signals, so I moved to a different room and ran the test; however, the SNR stayed the same. The SNR is always high, regardless of whether the headset is on or off. I also wonder if the issue is that I am utilizing Dry Comb electrodes, instead of wet electrodes for this task.
It is hard to pinpoint what the exact issue is, which is why I came to this forum.